


Underfell! You're Going to be My Pet( Sans X Oc/reader )

by Lyricata



Category: Undertale (Video Game)
Genre: F/M, Reader Is Not Frisk
Language: English
Status: In-Progress
Published: 2016-06-28
Updated: 2016-06-28
Packaged: 2018-07-18 20:33:14
Rating: Teen And Up Audiences
Warnings: Graphic Depictions Of Violence, Rape/Non-Con, Underage
Chapters: 8
Words: 4,038
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/7329721
Author URL: https://archiveofourown.org/users/Lyricata/pseuds/Lyricata
Summary: <blockquote class="userstuff">
              <p>You fall to the underfell and become Sans pet. Slowly you start liking his company, but is that your happy ending.<br/>Or will there be some events preventing your happy ending.<br/>What happens to your brother soul and what will you do.</p>
<p>Also on wattpad</p>
            </blockquote>





	1. My first meeting

Your pov.

I finally exited the ruins. I felt bad leaving Toriel alone, but i had to find a monster capable of strong magic, so i can create new body for your brother or make him come back from death. His soul was hidden in my bag.

I went along the road. You had a feeling that someone is watching me. But i keep walking cautiously.

''Hey sweetheart,turn around..'' i hear a voice.  
I turn and slip. The soul hidden in my bag falls out and I desperately try to catch it before the voice owner sees it. But you fail.

''Oh sweetheart what are you hiding there?'' I  rise up from the ground unable to reach it. You just struggle.

''Give it back! Give it back!'' I scream in vain.'' Who are you to do this?!!'' I scream louder.

''Oh my name is Sans. It's a big surprise that you don't know.'' He smiles whit a smile bigger than before.'' Also keep you voice down you don't want the fun be spoiled by my brother, sweetheart? Also I'm not going to give that soul back. It's the last soul that we need. And i rather keep you than kill you for your soul.'' I feel myself lifted into the air and moved near him, he puts his hand on my chin and stares right in to my eyes. I felt frightened and scared.

''Sans you lazy bones. What is this wracked and noise? Why aren't you doing your job?'' I see a tall skeleton. And that adds you more fear if that is  even possible.'' Oh you cough a human?! Well i guess you aren't so useless time to time. Well hand the human to me.''

''Sorry boss, i won't give her to you.'' The small skeleton said.

''What, you are disobeying my order Sans?'' The tall skeleton looked angry.

''No way boss. I just have something better.'' The soul of my brother goes next to the high skeleton. ''This is a humans soul. The last one we need right. So we don't have to kill her right now. We can play whit her a bit before that don't you think boss?

''FINE THE GREAT PAPYRUS WILL GRANT YOU THIS FAVOR, LOCK HER IN YOUR PRISON NOW. AND WE CAN TALK ABOUT THIS LATER.'' The skeleton said.

''No stop give him back. Give his soul back to me!'' I'm finally able to talk again.

''SHUT UP HUMAN. SANS LOCK HER UP.'' Papyrus seemed angry.

''Alright boss'' Sans said. And the next moment you knew you were looking at Sans behind the bars.

''Huh? Where am i? Give me back my brother you monster!'' I scream loudly.

After a moment I feel pain in my chest. I look down and see a bone stuck. As my HP is lowering and I slowly lose your conscious screaming in agony.

''Shut up you're too loud'' He says and my vision gets dark. coldness covers me and my HP hits one.

 

**Notes for the Chapter:**

> I tried fixing this chapter a bit hope you liked the changes(if someone is rereading this)i will try to edit all the chapters.


	2. Pet

Your pov.

I woke up, my body felt heavy and it hurt a lot. I noticed something squishing my throat. I put my hands on my neck and i touch something like a collar whit a lock. 

I look around and see a mirror. When i look at it i see a red bright collar whit a golden lock that keeps it in place. I tried to loosen it a bit but it didn't work.

''For now i should just explore'' i sigh.

I was in something like a prison. The wall was thick and didn't seem to let any sound pass through. The bars of the prison were made of metal. So it was no use trying to brake them. The door was also locked. 

There was a toilet and a curtain airbags that slides when pulling. Also there was few small windows high above, so the sun was able to shine through.

There also was a dog bed. It was a bit small for me, but i guess it had to do if i was to stay here.

In short the place was quite neet. In fact it was better than few places i had to stay.

''So you finally woke up.'' I heard the door open and saw a small skeleton, Sans was it.''So whats new?'' Sans asked.

I sat on the dog bed and starred at him.

''Hey sweetheart why are you giving me a cold treatment? Don't be cold to the bone.'' Sans tried to joke nervously.

I continue to stare at him.

''Okay I'm done playing nice.'' Suddently he teleports just before me and i almost fell down but he caught me by my chin. ''Look sweetheart you're going to answer when i talk, to do wthat i tell you cuz now you belong to me. Got it girl?''

I slowly nod. He's scary. I liked him more before. But i guess it's good to see his true colours before anything.

''Okay change.'' He gives me a bag of clothes.'' I'll be back soon whit dinner.''

And he's gone. You went near the toilet and closed the curtain in case he comes back.

The bag had a pair of black jeans, a sleeveless T-shirt whit red roses in the corner. And a dark red jacket. Quite decent and it fits the style of the monsters.

I put the clothes and hear.'' I'm back sweetheart did ya me?'' Sans speaks.

''Not really.'' I say hoping he won't get angry.

''Oh thats sad Nora.'' Sans says. Wait Nora. Who's that? Is that me? 

''My name isn't Nora it's [y/n]'' i almost shout.

''Well bad for ya, cuz now it is Nora'' Sans leans down to me, puts his hand at the back of my head and kisses me. Not whit a normal kiss, but whit a tongue. He puts his tongue in my mouth and our tongues start to o dance. I can't do anything just stand there and wait for him to finish. ''If you still don't get it let me make everything clear you're my pet now Nora.'' He smiles whit a develish smile.'' Now eat my brother worked hard to make it for you Nora'' He puts spaghetti next to me and dissappears again.

I'm blushing like crazy thinking what i got myself into.

Sans pov.

''So she doesn't remember anything, does she?'' Papyrus asked.

''Nope'' 

''So what are you going to do Sans?''

''Just play whit her. Well she doesn't remember or recognise us so it will be fine.''

''Sans..''

''Yes Paps?''

''Just do whatever you want''

 

 

Okay so i hoped you liked it. Also in this fanfic character that's you look like Frisk. But well your hair is a lot longer. And you kinda have underfell style. And Sans calls you Nora. And I'm doing all of this cuz I'mjust lazy to do [~] on my phone while writing. So hope you aren't mad or anything.

P.S. 

I thought of name Nora cuz it kinda sounds like wish in my language.

Also in povs. the way i address will be:

Your- I  
Third persons- you.

Hope it will be easier fir you to read.


	3. Peek in the underground

3rd person pov.

You been here for quite a while. You started to know Sans better, but also you had dreams of him killing you. You didn't new if he was a friend or a foe... Of course he's a foe! He trapped you in this cell, he took your brothers soul. But he is a good person deep inside you believe in him. Despite the torture and his indecent moves towards you, like kissing or touching you... You decided to show him mercy, no matter what he will do to you. He reminded you of someone you forgotten...

Your pov.

''Sup sweetie.'' I heard Sans say. I was still sleepy.'' We're going for a walk. You're ready? '' I saw him hold a red dog-lead.

''A walk? Where are we going?'' I was a bit curious. I didn't have the time to explore the underground.

''My brother wants you to solve his puzzles. He was nagging me for quite a while. ''

''Um.. okay and the dog-lead is..'' I asked not finishing the sentence.

''Of course for you. Come on.'' He put it on my collar and we teleported ti the place where i first met Sans.

''SANS TOOK YOU LONG ENOUGH YOU LAZY BONES. HUMAN I'M THE GREAT PAPYRUS WILL LET YOU SOLVE MU PUZZLES. AND MAY GIVE YOU A CHANCE TO FIGHT ME SO PREPARE FOR THE CHALANGE. NEY HEHEHE..'' he turned around and walked further.

''Okay you may go. Don't worry if you'll need my help I'll assist you if you'll need my help Nora. You're my pet aren't you.'' He said and disappeared.

Guess I'll have to move forward.


	4. Puzzles

Third person pov.

You walked passed all of Papyrus and Sans puzzles. They were quite easy. Except that one when Papyrus rearranged when he was bored. That onr was a bit more difficult than the others.

Papyrus looked irritated that it took so long also he was angry cuz were able to solve them. That was really confusing indeed.

You preceded to walk to the last challenge. It didn't appear anything. A bridge that looked ordinary and two skeletons in the end of it.

''HUMAN BE PREPARED TO FACE YOUR BIGGEST CHALANGE YET.'' Papyrus spoke and pressed a red button on some kind of remote.

And then shit started to go down. Canons, fire shooting tingys, dogs and more dangerous looking things. Wait dogs?.. Whatever it looked dangerous really dangerous.

How come this is a puzzle? It's more run and see if u can survive test. You thought.

You slowly started walking when everything started moving and you started running for your life.

Finally you reached the end of the bride in one piece. Suprisingly...

''YOU SNEAKY HUMAN PASSED ALL MY PUZZLES. NOW PREPARE TO FIGH ME, THE GREAT PAPYRUS!!!!''

The action bar poped out

♡Fight ♡Act ♡Item ♡Mercy 

You choose act and checked him. It's going to be a long fight cuz you didn't want to fight him.

~Time skip 

''HUMAN IS THIS REALLY EVERYTHING YOU GOT?!!'' Papyrus looked disappointed at you. You were about to die. Your HP was showing 1/20. One more hit and you're finished. ''SO I THE GREAT PAPYRUS WILL SPARE YOU.'' You spared Papyrus.

''SANS! TRAIN THE HUMAN BETTER. SO THE NEXT TIME WE WOULD HAVE TO FIGH SHE WOULDN'T BE SO WEEK. I DON'T NEED ANOTHER DISAPPOINTMENT IN THIS FAMILY.'' Papyrus left and you were alone with Sans.

'' Guess you're a part of our family Nora. Looks like Papyrus excepted you. And guess we will have to star your training tomorrow cuz you cant even dodge a skele-ton of bones.'' Sans was talking while you two were walking to Snowdin and cracking puns.


	5. Training

Your pov

A nightmare that didn't seem like one. You, Sans and a flower were in a strange hall. You tried convincing Aans to stop and be good, but he continued to trow bones and fire at you.

This wasn't my first nightmare... You thought surrounded by darkness after when you were killed again... Timelines ... Is this the reason you don't stay death?

''Hey Nora wake up'' Sans was shouting and violently shaking you whit his red magic.

''I-I-m A-a-w-w-a-k-k-e now!!!'' You tried speaking and he made dissappear his red magic when you still were in the air. It made you bump your butt pretty hard when you fell from a hight.

''Oh now you're falling for me.'' He started to giggle.

''Sans that hurt. Also why were you doing that.'' You gave him a mean look.

''Doing what?'' He grined. And you knew he was thinking about something dirty.

''You know what! Shaking me like a maniac..''

''Well i tried to wake you up, but you still didn't want to wake up. So i started doing that. Or would you prefer a kiss to wake you up?

''Your kiss means let me stik my tongue as deep as i can and try to suffocate this little girl.'' You said sarcasticly putting your arms on your chest.

''Oh that reminds me my little pet girl didn't get her morning kiss.'' He came near you lean a bit and then your tongues met and started dancing again. He was brutal and more forceful then usual. It felt nice and you didn't want to disturb it as i always do. So the kiss went longer than it usually did.'' And you say you don't like it.''

''I didn't say i didn't like it'' you said.

''So you like don't ya sweetie?'' He was really close to you and you were cornerd.'' I won't let you go till you answer.'' He said whit a devilish grin on his face.

''Fine this time it felt quite nice. But i don't really like it.'' You said blushing a bit.

''Whatever you say Nora.'' He said it as if he didn't care and leaned again kissing you a bit more gentle and that made it even more enjoyable.'' If you will sand on your feet at least for an hour i will make something special.'' An evil grin was showing on his face when the red pupils disappeared and his face got darker.

''So were are we... ahhh'' you sream when he suddenly grabbed your hand and teleported you.'' What's this place?''

''Oh just a place where i can teach you privately.''

''Can you please stop doing those sex references?'' You were getting quiye annoyed by it.

''Nope no can do. Also i will start easy, but it will get harder. '' he started doing it purposely.

''Oh god can we just start this training?'' You were growing inpatient.

h/c heart appeared and you were able to see 4 buttons. You pushed ACT and it gave you choices- check *flirt *start dodging. You pushed the third button.

''You know you're hurting, i was sure you will use flirt or check me. Oh well lets begin this show.'' His red eyes dissappear and pupils became black again as the bones and gaster blasters began attacking.

Time skip brought by a lazy author.

The battle continued more more than an hour.

''Are tou sure you didn't held back before my brother?'' Sans asked.

''I'm sure.''

''So how the hell did you even survived that long?'' He looked weary curious and shocked. And began sweating.

''Guess i really wanted your special surprise.'' You joked as you were in the cell whit him.

''Guess i will need you to give it later y/n.'' He said whit a grin and dissappeared.

That was the first time he called you by your name.


	6. Special suprise

Lemon warning. So if you're not ready for this please leave.  
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Third persons pov.

You were sitting and waiting for Sans to come back. You were bored out of your mind, but you were too lazy to do anything. So you just sat there staring at one spot when suddenly Sans was standing a meter away.

''So are you ready ro begin your special suprise?'' Sans grined and smiled like a sadist. You saw ropes and chains.

''Sans what are those for.'' You gulped. Cuz you knew what those exactly were. Those ropes were to tide the person so it couldn't move and the other could sexualy abuse and give you ''pleasure''. You didn't what this kind of suprise.

''Oh it's your reward. And i hope you going to enjoy.''

''Sans i don't want to do it.'' You tried to stop him but he didn't listen and the red magic of his were talking your clothes leaving your panties and bra and teing the ropes.'' Please stop...'' tears were forming in the corners of your eyes.

''It's not what you want. It's what i want. And that's you.''

Sans started to lick your tears then moving to the neck. It tickled but you couldn't move and started tofeel your cum is about to burst out.

''Sans...''you started to moan.

''Oh so you do like it''

He kissed you and you started dancing with your tongues again. You didn't stop. You wanted to make the kiss last. You leaned as much a possible and not giving him time to fix his breathing you kissed. He was a bit surprised, but he didn't seem lost and excepted your kiss. 

When he finally pulled back a long line of drooled hang. It shone in bright red colour.

''So you like this my little naughty pet.'' You hesitate to nod.'' Don't be shy, i know you like it's written all over your face.'' You slowly nod.'' Good. Now be a good pet and beg for more.'' He slowly starts licking all over you.

''Sans... more... please'' you moan in pleasure. The liquid, the cum starts spilling making your panties wet.

He slowly puts his bony finger behind your f/c panties. His hand is covered in cum and he slowly starts licking it.'' It tasted delicious, you're delicious.'' He gazes into your eyes and a bright red blush dyes your face. His dreamy expression and eyes filled whit lust.

''Sans.. give ..me ...more.''you groan.

''Good, wery good Nora'' he starts licking your stomach squeezing your breast trough your bra. You can't help but to moan of how great it feels.

Soon you were covered in red saliva from his mouth, and now you were kissing. You wanted to grab him and push him closer. But you couldn't your arms were tied behind your back to your legs.

''So do you like your special reward? Or am i the only one enjoying it?'' His smile was so seducing and you could help it you just wanted to kiss him.

''No...'you shake your head.'' I like it.''

''Oh you're really naughty aren't ya sweetie?'' You blush.'' But i guess the the fun is over. I had enough today and you still have to do your training tomorrow.'' He untied your hands and you slowly move them to your chest.'' Get some rest, maybe we will try something different tomorrow.'' A devils grin brightens his face and he disappears.

Your pov.

It was so good and felt so familiar. His boney hands were dancing trough my body, squeezing my chest. His tongue was all over my body. His kisses seemed so lusting like he found something long gone, that he was searching.

This thing didn't get that far, but i wouldn't have minded if it was whit him.  
I were raped and used many times before, but encounters with him even if they got that far i wouldn't call them rape cuz i really wanted him to do it.

Three week didn't seem to be a long time to know someone to be able to do this so freely. I knew him longer than that.

Timeliness the memories of him and me rushed trough my head and i feel asleep not being able to stand the pain.

Sans pov.

I teleported myself into my room. I was red as a tomato.

''Did i really dis this? I could have at least asked her... She doesn't even remember anything about timeliness and us. Shit i hope won't think that was strange and try to reset, although she can't control it anymore.

 

I'm so red right now. I hope you liked this chapter cuz i really liked writing this chapter. But now i can feel sins crawling on my back. Sorry if you didn't like it. If you have any advices please write me or leave a comment. Hope you enjoyed. 

~Red tomato author

P.s word count 822


	7. Truth

Third pov.

You woke up and you still were half naked and covered in something shiny red that was left on your skin.

You look for your clothes quickly and blush in a bright red. Why did you let him do that. Well you didn't have the choice but still. You could have tried to show some resistance. But all you did was enjoy it and want more.

You dressed and tried to remove the red shine but it didn't go away. You were so embarrassed. How will you face Sans and those memories of timeliness does he remember it.

''Oh Nora you look red today'' He leaned to your ear making you uneasy, cough, embarrassed, confused. You tried to get away feom gim but he grabbed you.'' Do you really think you can escape my little tomato? ''You nod and he starts licking behind your ear.''Nah you're mine did you forgot that?''

''Can you please let go.'' You said in not a slightly confident voice.

''So will you try to escape? Do you not like being like this my little sinner? My pet. You shouldn't be embarrassed what happens between us stays like that got it?'' He speaks with a seducing voice.

''Okay...'' you're still looked like a tomato but you felt much more safer this way. His voice was so deep and could make almost everyone geel better.

''Good girl..'' he lifts your chin. And kisses you. His tongue had more droo and it tasted even sweeter.. 

''Sans this isn't our first time meeting. Timeliness we met in other them didn't we?'' He slowly backs of his pupils got dark. He looked scary.

''So you remember huh? Did you just played me for a fool then?'' His voice sounded dark.'' You always do it don't you?''

''I don't remember everything... I started getting weird dreams and stuff like that....'' you wanted ro explain everything to him.

''Just shut the fuck up!!!'' He used his red magic to slam you to the wall.. hard.'' You always do this we get close, everyone is happy and good. But you you reset and it goes away. Why! Why! Why!....''he slams me repeatedly till my HP is 1/20.'' Why... did you do it. Why do you just like playing with us? ''He cried letting go of your soul.

''Sans...'' you spit out blood.'' I'm sorry. I must have done terrible things, trough i don't remember it. When i arrived i didn't have any memory of time lines. And i don't know why i do all those resets. But i don't want ti reset this.'' You tried standing but you couldn't.

Sans pov.

Maybe I've gone overboard. But she could just reset if she dies. I love her so much, but i... i can't take all these resets.

''Please don't make any resets...'' i hug her.'' Please y/n... I love you and i don't what to start this again.'' She hugs me back and nods.'' Let's go we should patch you up.'' I giggle slightly and kiss her on the forehead.

 

Sorry it took so long to update hooe u liked it and if you want lemons just ask. (I'll try) Sorry for the emotional chapter.


	8. Spaghetti

Your pov.

After the incident with Sans he offered me a bath i gladly agreed. I still had red saliva stuck in me so it was really refreshing. I also got new clothes. 

A short black skirt and black leggings with cuts on the knees. And a tight black top. I still had the jacket.

''You're done already?'' He ask and i slightly nod. It was awkward to be near him.

The silence was interrupted by my stomach growling. I start to blush.

''Guess you're hungry.'' I nod.'' But sorry all we have is Papyrus boxed pasta''

''That will do if you don't mind me eating it.'' I ask shyly.

''Go a head Paps always complains that no one eats his cooking so go ahead.''

Time skip 

I already ate 4 boxes of spaghetti.

''Wow you sure have an appetite for this gross spaghetti.'' Sans said with a grin.'' How can tou even eat this gross shit?''

''Well it's quite decent compered to things i ate on the surface.'' I say looking at my spaghetti.

''Really like what?'' He looks interested.

''Well like...'' i couldn't continue my sentence because Papyrus walked in.

''OH HUMAN I SEE YOU ENJOY ME SPAGHETTI.''he says as loud as possible.''SANS YOU LAZY BONES YOU SHOULD ALSO APREACIATE MY COOKING AS THE HUMAN DOES.

''Boss...'' Sans couldn't say anything because Papyrus kept talking.


End file.
